Nurling-tool.



J. ARMSTRONG.

N URLIN G TOOL.

APPLICATION FILED snr'r. 1a, 1908.

960,769, Patented June 7, 1910.

W Wig y wfim UNITED STATES PATENT OFFICE.

JAMES ARMSTRONG, OF MAYWOOD, ILLINOIS, ASSIGNOR TO THE ARMSTRONGBROTHERS TOOL COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

NURLING-TOOL.

To all whom it may concern:

tie it known that I. JAMES ARMSTRONG, a citizen of the United States.residing at .\Ia vwood. in the county of Cook and State of Illinois.have invented certain new and useful Improvements in Nurling-Tools, ofwhich the following is a specification.

The object of this invention is to produce a self-centering nurling toolor other similar device which shall be simple in construction, strong.and inexpensive to manufacture.

In the accompanying drawings, Figure l is a side elevation of a nurlingtool embodying the features of my invention. Fig. 2 is a side elevationof the forward end of said tool with one side of the rotatablediecarrying member sectioned away. Fig. 8 is a front end elevation withone of the dies in section. Fig. 4 is a front end view of the tool withthe die-carrying member removed. Fig. :3 is a sectional view on dottedline 5 5 of Fig, l.

The embodiment selected for illustration comprises a holder 1 consistingof the shank 01' securing portion 2 and means at the forward end of saidshank for rotatably supporting a die-carrying head 3. In this instancesaid supporting means comprises a socket 4 having a curved web or rlb 5arranged centrally thereof. The die-carrying head 3 is generallycircular in outline to fit within the bearing socket l and has a groove(3 therein to receive the curved rib 5, the bottom wall of said grooveand the forward edge of said rib sliding in contact with each other andbeing curved on the arc of a circle. The head 3 is secured to the bodyof the tool by means of a pin 7 extending through said head and througha curved elongated opening 8 in the rib 5, which opening is concentricwith thepivoi'al center of the head 3. The oscillator movements of thedie-carrying head 3 are limited by the engagement of said pin with theend walls of the elongated opening 8. For convenience in removing thehead 3 the pin 7 is preferably made readily removable, said pin, asherein shown, having a driving taper fit within the openings 9 of thehead 3; those portions of the pin which lie within said openings aretapered, the central portion of the pin, namely that which lies withinthe elongated opening 8, being prcferal'ily cylin- Specification ofLetters latent.

Application filed September 18, 1908.

Patented June '7, 1910.

Serial No. 453,620.

drical. When it is desirable to remove the head 3 the pin 7 may bereadily driven from its place.

i The die-carrying head 3 is herein illustrated as equipped with nurlingdies or knurls 10, although it will be understood that other tools maybe substituted therefor. The dies 10 are rotatably supported within therecessed forward end of the head by pins 11 passing through openings 12in said head. For ease in replacing worn dies the pins 11 preferablyhave a driving taper fit within the openings 12, as in the case of thepin 7; the portions of the pins 11 which lie within the openings 12being tapered and those portions which constitute pivots or shafts forthe dies 10 being cylindrical.

As an aid to the workman in properly securing the tool in the lathe orother machine, gage marks 13 may be formed upon the head 3 and itssocket.

In order to lighten the tool, the shank 2 is preferably made somewhatthinner or more slender than the socket head, and the sides of saidshank may be recessed to give the shank a cross-sectional I-form, thusconsiderably reducing its Weight Without materially impairing itsstrength.

In use, the shank of the tool is secured in the tool post of the latheor other machine,-

and the tool placed in operative position with the dies 10 pressedagainst the work. As the work is rotated, its surface is knurled by theaction of the dies 10. The head 3, being rotatably mounted, is free tocenter or adjust itself to the work, The bearing socket 4 affords alarge and firm bearing for the head. The long rib and groove connectionbetween the head 3 and the body of the device effectively withstands anyside strains imposed on the tool in practice. The socket 4 with itscurved central rib 5 may be conveniently and accurately formed bymilling.

I claim as my invention:

1. A nurling or similar tool comprising a socket having a curved centralrib, a diecarrying head mounted in said socket and grooved to receivesaid rib, said rib having an elongated opening therein, and a pin fixedin said head and extending into said elongated opening.

2. A nurling or similar tool comprising two parts, one of said partsbeing a member having a socket therein, the the other part being adie-carrying head fitting rotatably in said socket; and means forsecuring said parts together comprising a pin fixed in one part andextending through an elongated opening in the other part, saidelongatedv having the roove and' extending inte said elongated opening.

4. A nurling or similar tool comprising a 20 socket, a central rib insaid socket, the for- Ward edge of said rib being curved on the arc of acircle concentric with the circle upon which said socket is formed, saidrib having an elongated opening therein, a die-carrying 5 head rotatablyfitting in said socket and hav ing a curved surface contacting theforward edge of said rib, and a pin fixed in said head and extendingintosaid elongated opening.

JAMES ARMSTRONG.

Witnesses:

J. H. ELISCHER, F. R. SCI-IERFFINS.

